Static and dynamic blanking of steel of varying hardness

Abstract Experiments are described in which steel plate, of constant composition but hardened to varying degrees, was blanked both statically, using a universal testing machine, and dynamically, using a punch fired from an industrial gun at a velocity of the order of 300 ft/sec. Graphs are presented showing the dependence of major parameters such as energy, penetration, punch force/displacement characteristics, upon the hardness of the stock material, for both the static and dynamic operations. Results of tensile and Izod tests upon specimens of varying hardness are also presented and the ductile/brittle transition in these results is seen to be associated with a number of features of the blanking tests. Photographs of statically and dynamically blanked specimens are included.